> Converted multifamily residences from electric resistance heat to gas-fired hot water heat to reduce operating costs and greenhouse gas emissions. The electric heat was installed when nuclear power was going to make electricity "too cheap to meter" (but also GHG-free). Instead ISO-NE's grid currently makes 50% of it from natural gas at ~40% efficiency, while the onsite heating boilers are ~90% efficient.> Converted central plant, steam heating systems to decentralized hot water heating systems to reduce operating cost and greenhouse gas emissions. The old systems were so inefficient that getting 40% savings was like shooting fish in a barrel.> Engineered solar photovoltaic systems including layout, cost estimating, and utility interconnection applications for municipal rooftop, parking canopy, and ground-mount arrays.